kerklein2
Well-Known Member
Hmmmm...good point. Although that really brings up a problem with people using pressure to measure volume. It varies with gravity. If you had a level sensor and a pressure sensor you could calculate volume and gravity.
All-Grain Brewery w/Automation--Concept Phase
- Thread starter kerklein2
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
Hmmmm...good point. Although that really brings up a problem with people using pressure to measure volume. It varies with gravity. If you had a level sensor and a pressure sensor you could calculate volume and gravity.
With a big enogh element, yes. From what I have read sparge rate is around 1 qrt per min. (JP how to brew, i think), so low flow plus lots of power = enough temp rise.
Power = Specific heat capacity . density . volume flow . temp change
6000w element, assume 85% eff = 5100w heating
5100 = 4180 x 1000 x 1.67 x 10^-5 x delta_T
=> delta_T = 73
back of napkin calcs so don't trust me that it is 100% true
The pressure sensor method of kettle volume works well, if you are concerned about accuracy then a scaling factor can be applied based on liquid temperature. A 2 PSI wet pressure sensor can be found on Ebay, and when remote mounted to avoid heating it should work well. For the low flow rate of the sparge the RIMS heater is more than adequate for heating water to 175 degree sparge temperature.
Sawdustguy
Well-Known Member
Not really. The brewtroller can do four PID functions which can control SSR's directly for heating elements, control 16 relays directly, if you need more than 16 a multiplex board is available, reads 3 pressure sensors for volume measurement and reads five one wire temperature devices. An external board is being developed to interface RTD's also. It comes preloaded with software developed to automate the brew. Inexpensive yes, cheap, no. You can buy one for under $100.
Brewtroller comes with Rotary Encoder and LCD Display with software preloaded
16 Port Relay Board for controlling Relays and Pumps
Sawdustguy
Well-Known Member
National Instruments was my guess also. I used to work very closely with some of the NI guys when I worked for Tektronix.
It would be interesting to see the capabilities of the software package for the I/O hardware, HMI interface, control loop capabilities, data storage and retrieval. It would be a bit of a problem if flexibility was not there for repurposing it for brewing system control applications.
kerklein2:
How much money are you willing/able to spend out of pocket on your system? If your company is only furnishing some measurement and control devices, you'll be footing the bill for that vast majority of the system.
If I generalize my HERMS system and call the little toggle switches, PID, and temp probe my "measurement and control" devices, then that amounts to only about $60 of the total system cost (which is probably $500 dollars in total.)
How much money are you willing/able to spend out of pocket on your system? If your company is only furnishing some measurement and control devices, you'll be footing the bill for that vast majority of the system.
If I generalize my HERMS system and call the little toggle switches, PID, and temp probe my "measurement and control" devices, then that amounts to only about $60 of the total system cost (which is probably $500 dollars in total.)
kerklein2
Well-Known Member
The flexibility is pretty endless honestly. I encourage you to check out http://www.ni.com/labview/. This software is used in pretty much every industry out there for pretty much every application you could think of. Its basically its own programming language. The hardware and software are both designed by NI to work with each other, and LabVIEW is designed to create great user interfaces very easily.
kerklein2
Well-Known Member
I haven't figured out a budget yet since I haven't decided on a system yet. Like I said, I already have two coolers and a 32 quart pot. My pot already has a valve on it and I have a counterflow chiller (although if I go HERMS, I'll like use that coil for cooling). Once I decide on a system and start piecing it together, I'll get a better idea of how much this is going to set me back. I did find the cheap solenoid valves on eBay, so that has got me thinking about using valves everywhere.
I'll tell you one major place that I neglected to estimate costs properly: power cables.
After looking at them for a while, I didn't want to use the dryer or stove appliance cables you can find at Lowe's because they are REALLY stiff and short (only 4' or 6' long). I ended up buying flexible, portable power cables and suitable plugs for the ends for them.
Power cable costs can start creeping up towards $100 pretty quickly. Just the 15' long main feed coming into my system (with a plug on it) cost about $50.
That $500 number I quoted there is just for a control box, electrical stuff, and a pump. It does not include my mash tun or keggle in the costs.
After looking at them for a while, I didn't want to use the dryer or stove appliance cables you can find at Lowe's because they are REALLY stiff and short (only 4' or 6' long). I ended up buying flexible, portable power cables and suitable plugs for the ends for them.
Power cable costs can start creeping up towards $100 pretty quickly. Just the 15' long main feed coming into my system (with a plug on it) cost about $50.
That $500 number I quoted there is just for a control box, electrical stuff, and a pump. It does not include my mash tun or keggle in the costs.
kerklein2
Well-Known Member
Hmmm...I hadn't thought about power cables being so expensive, but I guess 10AWG has a lot of copper in it and those plugs are probably expensive too.
Sawdustguy
Well-Known Member
Labview is the standard for easy instrumentation control. HP tried to give competition in this arena with their HP VEE (Visual Engineering Environment) but failed early on because you could not make an executable. You needed the VEE runtime version to run a program. Eventually they came up with a executable version, but by then it was too late. I used to sell VEE when I worked for HP selling T&M equipment in the early 90's (not Agilent). Almost every instrument that I know of with an IEEE 488 interface has a labview driver. It also has the capability of doing direct I/O if a driver is not available and some sort of driver writing tool. Even though it is a neat piece of software it is way beyond what we could afford as homebrewers.
I worked for HP when they spun off Agilent. It went downhill pretty quick after Carly took the reigns from Lew Platt and I left in 2003. RIP "HP Way."
kerklein2
Well-Known Member
Plastic or SS?
316 SS and brass. I use the 1/2" high-flow style quick disconnects... like these.
EDIT: I can't figure out how to link to the right page at McMaster - but I bought all of mine locally.
kerklein2
Well-Known Member
The hose-barb ones are cheap, but damn, the pipe thread ones are not!
jfkriege
Well-Known Member
I use Labview at work for controlling some testing equipment I made for my lab. It is great software.
I think phase 2 of my brewery is going to have labview and a labjack controlling my rig. Being a student I get labview for $79. You might look into taking that class you always looked at at your local community college.......
I guess I have had a sheltered carreer, I have not encountered the NI equipment or software in the industrial facilities. Most of the systems encountered have been AB,Emerson, Siemens, Rockwell,Bailey, Ge, Honeywell , Opto 22 , PLC systems.
Huh? What does the temperature have to do with getting a correct reading. The gravity is different from water because it is wort and not water and you can not be 100% sure what the gravity is, could lead to around 1 gal difference. Plus you would have a whole lot of grain in your mash tun taking up space (again not 100% how much) so that would effect the final "height" of your calculation. I would use a level measurement over the presuure calculation method if I was looking for accuracy and repetability, I admit the pressure method would wins on cost.
What measurement/sensors does NI have in their product range (I am having issues finding stuff on the website, probably becuase I don't know what to look for, damn mechanical engineers trying to play with the EE imaginary toys aye
)
What is you job desciption as a mech eng at an instrumentation company?
I work as a mech eng in a small engineering services department of a chemical company and I have had to learn more about the other diciplines since starting here (just finish my first relay logic for controling some safety gates)
)What is you job desciption as a mech eng at an instrumentation company?
I work as a mech eng in a small engineering services department of a chemical company and I have had to learn more about the other diciplines since starting here (just finish my first relay logic for controling some safety gates)
kerklein2
Well-Known Member
What measurement/sensors does NI have in their product range (I am having issues finding stuff on the website, probably becuase I don't know what to look for, damn mechanical engineers trying to play with the EE imaginary toys aye
We don't sell sensors (except a few thermocouples I think) but we can measure pretty much anything. You kind of have to know what you are doing to navigate our website because of our broad range of products, but we have a very helpful applications engineering department if you call the guys up.
My job description centers around enclosure design of our electronic products, but it involves all sorts of other things.
Now the website makes more sense, as I said a case of a mech engineer looking for stuff that he didn't know shouldn't/wouldn't be on there.
I think I remember LabVIEW (or something that looks very simular) from the controls coarse at uni, did basic PID control and feedback loops for 3 tanks with 2 pumps draining into a sump.
Anyway I will let this get back on topic!
I think I remember LabVIEW (or something that looks very simular) from the controls coarse at uni, did basic PID control and feedback loops for 3 tanks with 2 pumps draining into a sump.
Anyway I will let this get back on topic!
I went the pressure route for level measurement as a simple way to get a volume in water, mash, and boil containers, and use that for flow loop reset on mash to boil transfer during sparge cycle.
kerklein2
Well-Known Member
I just did some quick calcs and if your pressure sensor was calibrated for water and you actually had 1.060 wort in there, you'd be off by over .75 gallons in a 13in diameter tun. The higher the gravity, the worse the error. This seems to be WAY too much error.
taking it one step further, you would also include for the fact that you will have grain in the mash tun taking up space and therefore the height of the liquid for a particular volume will be higher leading to further errors in the calculation of water volume.
If money was no object I would have a setup like kladue's process description for the sparge, RIMS heater heating sparge water inline. The process would be pump from mash tun to BK with a flow meter in this line to determine sparge rate (flow meter would control automated ball valve to throttle flow after the pump), Level indicator to keep the level in the tun constant (controlling a automated ball valve to throttle the inlet water to the RIMS heater). Level indication on the BK and pressure so SG can be calculated. And if money was absolutly no problem a pH probe for the mash tun outlet to stop the sparge if pH gets to high(?) and maybe turbidity meter to check when the sparge runs clear.
jfkriege
Well-Known Member
It would not be too hard to have an excel sheet work out your actual volumes based on an SG reading taken from a refractometer.
I assume the correction would be linear as SG goes up. Does anyone know any different?
I assume the correction would be linear as SG goes up. Does anyone know any different?
The recipe building and calculations have already provided that based on the fermentables selected and quantities used. All that would be needed would be to add code to correct level based on gravity and temperature.
jfkriege
Well-Known Member
If he is going to have access to the best equipment around, why not have SG and temperature as measured values that are automatically fed back into the system. If you are going to go all out, then go all out.
I just clicked that even taking a level measurement for volume would be thrown by the grain (as it is still just a hieght X the expected surface area of the tun which is thrown off by the grain)
Only way to know for sure how much water is in there to begin with is a flow meter on the inlet.
I just looked at the concepts I have in the back of my notes book at work and the process for strike water was to have the flowmeter between the pump and the BK and a tee so you could either fill the BK with the pump or from the tap. measure the strike water into the BK, heat to strike temp, pump into mash tun.
The problem with using the expected gravity is that you can not be sure whether you are getting the efficiency you are estimating, yes it would be more acurate but still some error (you would probably survive it though
). It also ends up to having to estimate the gravity for every beer you brew, or at least select a few average gravities depending on style.
Only way to know for sure how much water is in there to begin with is a flow meter on the inlet.
I just looked at the concepts I have in the back of my notes book at work and the process for strike water was to have the flowmeter between the pump and the BK and a tee so you could either fill the BK with the pump or from the tap. measure the strike water into the BK, heat to strike temp, pump into mash tun.
The problem with using the expected gravity is that you can not be sure whether you are getting the efficiency you are estimating, yes it would be more acurate but still some error (you would probably survive it though
). It also ends up to having to estimate the gravity for every beer you brew, or at least select a few average gravities depending on style.
I went with dedicated water tank and level/volume measurement, fill to volume needed, pump until level is 0. Calculate water needed from batch size and malt quantity for strike, subtract absorption, calculate sparge volume to reach batch size+Boil off. Water measurements are usually at same temperature for consistency, level control is relatively easy way to get required volumes.
kerklein2
Well-Known Member
How would you recommend measuring SG directly?
So you take readings from the BK and the Sparge supply, nothing in the mash tun? Sounds like a effective way, the only downside I see is the estimating of the gravity in the BK (not so much of a drama) and the inability to calculate the gravity pre/post boil. Only other thought is jfkrieg comment, but when is enough, enough 
I have had too much time on my hands and have gone well beyond that, you have a batch setup screen and 3 ingredient screens for malt, hops, and adjuncts. Once batch parameters are entered you go on to malt entries, hop entries, and adjuncts. As entries are made the pre/post boil gravities are calculated, water volumes, SRM color, IBU's so you can watch and change as you go. When you are done with selections you can either manually control system or select auto sequence and walk away.
BrewBeemer
Well-Known Member
Back to basics a stamped and numbered as hot but the cold measurenent numbers on a stainless strip like a ruler a measuring stick. Stamp both sides for different keggle measurements, drill a hole and hang it on your rig. Simple and be done with it. I can see a LED with timer delay for the sparge process on automatic.
Sawdustguy
Well-Known Member
Pressure is a very accurate way to measure volume. The reason that temperature can affect the reading is as the air in the tube that goes to the pressure sensor gets warm the pressure in the tube increases. Here is a video using pressure sensors to measure volume.
Last edited by a moderator:
